1. Technical Field
The following description relates to a touch sensor integrated type display device, and, more particularly, a touch sensor integrated type display device capable of improving touch performance.
2. Discussion of the Related Art
In recent years, various input devices such as a keyboard, a mouse, a joystick and a digitizer have been used to interface between a user and home appliances or telecommunication devices. However, when a user makes use of the input devices, the user's dissatisfaction may increase because the user is required to learn how to use the different input devices and because the input devices occupy space. Therefore, a convenient and simple input device that can reduce erroneous operation is required. According to this desire, there is a touch sensor that can input information by directly contacting a screen with a user's finger or a pen while seeing the input devices.
The touch sensor has a simple configuration capable of minimizing erroneous operations. Also, the user can perform an input action without using a separate input device, and can quickly and easily manipulate a device through contents displayed on a screen. Accordingly, the touch sensor has been applied to various display devices.
The touch sensor used in the display devices may be classified into an add-on type touch sensor, an on-cell type touch sensor, and an integrated type (which is also called an “in-cell” type) touch sensor. The add-on type touch sensor is configured such that a display device and a touch sensor are individually and/or separately manufactured, and then the touch sensor is attached to an upper substrate or an upper portion of the display device. The on-cell type touch sensor is configured such that components constituting a touch sensor are directly formed on the surface of an upper portion of the display device, such as an upper glass substrate. The integrated type touch sensor is configured such that a touch sensor is integrated into a display device to make it a thin shape and enhance durability thereof.
The add-on type touch sensor causes the thickness of a display device to increase because the add-on type touch sensor has a structure in which the add-on type touch sensor is mounted on the display device. Further, visibility of the display device is reduced because of a reduction in brightness of the display device resulting from the increased thickness.
On the other hand, the on-cell type touch sensor shares the glass substrate with the display device because the on-cell type touch sensor has the structure in which the on-cell type touch sensor is formed on the surface of the glass substrate of the display device. Therefore, a thickness of the display device using the on-cell type touch sensor is less than a thickness of the display device using the add-on type touch sensor. However, the entire thickness of the display device implementing the on-cell type touch sensor increases because of a touch driving electrode layer, a touch sensing electrode layer, and an insulating layer for insulating the touch driving electrode layer and the touch sensing electrode layer which constitute the on-cell type touch sensor.
Accordingly, there is a focus on the integrated type touch sensor in that it is possible to achieve a thin display device and to enhance the durability of the display device, thereby resolving the problems of the add-on type and on-cell type touch sensors.
In general, a related art touch sensor integrated type liquid crystal display device displays images by adjusting light transmittance of liquid crystal using an electric field. For this, the liquid crystal display device includes a liquid crystal panel in which liquid crystal cells are arranged in a matrix type and a driving circuit for driving the liquid crystal panel.
The liquid crystal panel includes a color filter array and a thin film transistor (TFT) array with a liquid crystal layer interposed therebetween. The TFT array includes gate lines and data lines crossing each other, and liquid crystal cells disposed in areas defined by the crossing of the gate lines and the data lines. The TFT array includes pixel electrodes and common electrodes for applying the electric field to the liquid crystal cells. Each of the pixel electrodes is connected to any one of the data lines through a source and drain electrode of a TFT serving as a switching element. A gate electrode of the TFT is connected to any one of the gate lines to apply pixel voltages to the pixel electrodes line-by-line. The color filter array includes black matrixes and color filters.
The driving circuit includes a gate driver for driving the gate lines, a data driver for the data lines, a timing controller for controlling the gate driver and the data driver, and a power supplier for driving voltages of the display device.
The gate driver and the data driver may be integrated by using a plurality of integrated chips (ICs). The integrated gate driver ICs and the integrated data driver ICs are mounted on a tape carrier package (TCP) to be connected to the TFT array by a tape automated bonding (TAB) method or a chip on glass (COG) method.
The gate driver ICs or data driver ICs mounted on the liquid crystal panel, that is, to a lower glass substrate of the liquid crystal panel, by the COG method, and are connected to each other using a line-on-glass (LOG) method in which signal lines are mounted on the lower glass substrate. And also the gate driver ICs and data driver ICs receives control signals from the timing controller and driving voltages from the power supplier through flexible printed circuits (FPCs).
Hereinafter, a related art a touch sensor integrated type display device according to the COG method will be described with reference to FIG. 1. FIG. 1 is a top plan view illustrating a related art touch sensor integrated type display device.
With reference to FIG. 1, the touch sensor integrated type display device includes an active area AA displaying data and a bezel area BA disposed at outside of the active area AA. The bezel area BA includes wires and a gate driving circuit formed therein.
More specifically, the active area AA includes a plurality of data lines and a plurality of gate lines, a plurality of liquid crystal cells, a plurality of pixel electrodes, a plurality of common electrodes, and a plurality of thin film transistors. The plurality of common electrodes serve as touch driving electrodes and touch sensing electrodes.
A touch sensor disposed in the active area AA includes 1-1 to 1-4 touch electrodes Tx11 to Tx14, Tx21 to Tx24, Tx31 to Tx34, and Tx41 to Tx44; 1-1 to 1-4 sub-routing wires TW11 to TW14, TW21 to TW24, TW31 to TW34, and TW41 to TW44; and a plurality of second touch electrodes Rx1 to Rx3. The 1-1 to 1-4 touch electrodes Tx11 to Tx14, Tx21 to Tx24, Tx31 to Tx34, and Tx41 to Tx44 are divided in a first direction (e.g., the x-axis direction) and second direction (e.g., the y-axis direction), which cross each other. The 1-1 to 1-4 sub-routing wires TW11 to TW14, TW21 to TW24, TW31 to TW34, and TW41 to TW44 are connected to the 1-1 to 1-4 touch electrodes Tx11 to Tx14, Tx21 to Tx24, Tx31 to Tx34, and Tx41 to Tx44, respectively, and are arranged in the second direction. Each of the plurality of second touch electrodes Rx1 to Rx3 is disposed between first touch electrodes Tx11 to Tx41 and Tx12 to Tx42, between Tx12 to Tx42 and Tx13 to Tx43, and between Tx13 to Tx43 and Tx14 to Tx44, neighbored in the first direction.
The plurality of first touch electrodes Tx11 to Tx14, Tx21 to Tx24, Tx31 to Tx34, and Tx41 to Tx44 are connected to first connection wires (not shown), and a plurality of first main-routing wires TW1 to TW4 (shown as TW1a to TW4a and TW1b to TW2b) through the first sub-routing wires TW11 to TW14, TW21 to TW24, and TW31 to TW34, thereby forming a plurality of first touch electrode serials Tx1 to Tx4 arranged in the first direction in active area AA.
More specifically, the 1-1 touch electrodes Tx11 to Tx14 (arranged in a first row) are connected to each other by the 1-1 sub-routing wires TW11 to TW14 connected to the 1-1 touch electrodes Tx11 to Tx14, respectively; a 1-1 connection wire that connects the 1-1 sub-routing wires TW11 to TW14; and a 1-1 main-routing wire TW1 connected to the 1-1 connection wire, thereby forming the 1-1 touch electrode serial Tx1.
The 1-2 touch electrodes Tx21 to Tx24 (arranged in a second row) are connected to each other by the 1-2 sub-routing wires TW21 to TW24 connected to the 1-2 touch electrodes Tx21 to Tx24, respectively; a 1-2 connection wire that connects 1-2 sub-routing wires TW21 to TW24; and a 1-2 main-routing wire TW2 connected to the 1-2 connection wire, thereby forming 1-2 touch electrode serial Tx2.
The 1-3 touch electrodes Tx31 to Tx34 (arranged in a third row) are connected to each other by the 1-3 sub-routing wires TW31 to TW34 connected to the 1-3 touch electrodes Tx31 to Tx34, respectively; a 1-3 connection wire which connects 1-3 sub-routing wires TW31 to TW34; and a 1-3 main-routing wire TW3 connected to the 1-3 connection wire, thereby forming 1-3 touch electrode serial Tx3.
The 1-4 touch electrodes Tx41 to Tx44 (arranged in a fourth row) are connected to each other by the 1-4 sub-routing wires TW41 to TW44 connected to the 1-4 touch electrodes Tx41 to Tx44, respectively; a 1-4 connection wire that connects 1-4 sub-routing wires TW41 to TW44; and a 1-4 main-routing wire TW4 connected to the 1-4 connection wire, thereby forming 1-4 touch electrode serial Tx4.
A 2-1 touch electrode Rx1 of the plurality of second electrodes Rx1 to Rx3 is disposed between 1-5 touch electrodes Tx11 to Tx41 (arranged in a first column) and 1-6 touch electrodes Tx12 to Tx42 (arranged in a second column), thereby forming 2-1 touch electrode serial Rx1.
A 2-2 touch electrode Rx2 of the plurality of second electrodes Rx1 to Rx3 is disposed between 1-6 touch electrodes Tx12 to Tx42 (arranged in a second column) and 1-7 touch electrodes Tx13 to Tx43 (arranged in a third column), thereby forming 2-3 touch electrode serial Rx3.
A 2-3 touch electrode Rx3 of the plurality of second electrodes Rx1 to Rx3 is disposed between 1-7 touch electrodes Tx13 to Tx43 (arranged in a third column) and 1-8 touch electrodes Tx14 to Tx44 (arranged in a fourth column), thereby forming 2-4 touch electrode serial Rx4.
The first and second touch electrodes Tx11 to Tx14, Tx21 to Tx24, Tx31 to Tx34, Tx41 to Tx44, and Rx1 to Rx3 serve as common electrodes of the display device and are operated as the common electrodes in a display mode and are operated as touch driving and sensing electrodes for perceiving touch positions in a touch mode.
The bezel area BA is disposed outside of the active area AA. The bezel area BA includes data driving integrated chips (ICs) D-IC; gate driving ICs G-IC; flexible printed circuits FPC; data links DL; gate links GL; the 1-1 to 1-4 sub-routing wires TW11 to TW14, TW21 to TW24, TW31 to TW34, and TW41 to TW44; 1 to 4 grouping wires GR1 to GR4; the 1-1 to 1-4 main-routing wires TW1 to TW4; 2-1 to 2-3 routing wires RW1 to RW3, data line-on-glass (LOG) type wires D_LOG; and gate line-on-glass type wires G_LOG. The flexible printed circuits FPC are attached to one edge of the bezel area BA to deliver control signals and driving voltages supplied from the outside. The data links DL connect the data lines (not shown) in the active area AA to the data driving ICs D-IC in the bezel area BA. The gate links GL connect the gate lines (not shown) in the active area AA to the gate driving ICs G-IC in the bezel area BA. The 1-1 to 1-4 sub-routing wires TW11 to TW14, TW21 to TW24, TW31 to TW34, and TW41 to TW44 are extended from the active area AA to the bezel area BA. The 1 to 4 grouping wires GR1 to GR4 are connected to the 1-1 to 1-4 sub-routing wires TW11 to TW14, TW21 to TW24, TW31 to TW34, and TW41 to TW44 such that the 1-1 to 1-4 sub-routing wires TW11 to TW14, TW21 to TW24, TW31 to TW34, and TW41 to TW44 are respectively grouped. The 1-1 to 1-4 main-routing wires TW1 to TW4 connect the 1 to 4 grouping wires GR1 to GR4 to the flexible printed circuits FPC, with TW1a to TW4a being at one end of the 1 to 4 grouping wires GR1 to GR4, and with TW1b to TW4b being at the other end of the 1 to 4 grouping wires GR1 to GR4. The data LOG wires D_LOG connect the flexible printed circuits FPC to the data driving ICs D-IC. The gate LOG wire G_LOG connects the flexible printed circuits FPC to the gate driving ICs G-IC.
In the related art touch sensor integrated type display device, there are regions where the gate LOG wires G_LOG overlap at least one portion of the 1-1 to 1-4 grouping wires GR1 to GR4 at lower right corner of the bezel area BA. The gate LOG wires G_LOG are intensively disposed in a narrow area at the lower corner of the bezel area BA to connect the flexible printed circuit FPC disposed at the lowermost end of the bezel area BA to the gate driving IC G-IC disposed at the rightmost end of the bezel area BA because the gate LOG wires G_LOG are disposed between the flexible printed circuit FPC and the gate driving IC G-IC to supply gate control signals from the outside to the gate driving IC G-IC. Also, the 1-1 to 1-4 grouping wires GR1 to GR4 are disposed at a lower portion of the bezel area BA. Accordingly, the gate LOG wires G_LOG overlap at least one portion of the 1-1 to 1-4 grouping wires GR1 to GR4. In FIG. 1, the gate LOG wires are indicated as an area G_LOG where the gate LOG wires are disposed. Therefore, G_LOG indicates the gate LOG wires or the area where the gate LOG wires are disposed as desired for the device.
The grouping wires GR1 to GR4 are simultaneously formed with source/drain electrodes of thin film transistors of the liquid crystal display panel. The gate LOG wires G_LOG are formed when gate electrodes of the thin film transistors are formed, or when the source/drain electrodes are formed. Alternatively, the gate LOG wires G_LOG may be formed of a double layer including a gate metal layer and a source/drain metal layer. The gate metal layer of the gate LOG wire G_LOG is formed when the gate electrode of the thin film transistor is formed, and the source/drain metal layer of the gate LOG wire G_LOG is formed when the source/drain electrode of the thin film transistor is formed.
To obviate that the grouping wires GR1 to GR4 of the touch sensor overlap with the gate LOG wires G_LOG, it should be considered that a length of the gate grouping wires G_LOG is reduced or the size of the gate LOG area where the gate LOG wires is disposed is reduced.
However, if the length of the grouping wire (e.g., the grouping wire GR4 of FIG. 1) is reduced, there is a problem that a touch performance is deteriorated because at least one of the touch electrodes (e.g., the touch electrode Tx44) cannot be connected to the reduced grouping wire GR4.
Also, if the gate LOG area G_LOG is reduced, a cross-sectional area of each the gate wires are reduced, or it is impossible to form the gate LOG wires having the double layer. Accordingly, a total resistance of the gate LOG wires is greatly increased, which deteriorates performance of the display performance and touch performance.